Asymmetrik/ngx-starter

import { Directive, input } from '@angular/core';

import isEmpty from 'lodash/isEmpty';

import { AsyTableDataSource } from '../asy-table-data-source';

/** Interface for a directive that holds sorting state consumed by `AsyFilterHeader`. */
export interface AsyFilterable {
    /** The id of the column being filtered. */
    id: string;
    clearFilter(): void;
}

@Directive({
    selector: '[asyFilter]',
    exportAs: 'asyFilter',
    // eslint-disable-next-line @angular-eslint/no-host-metadata-property
    host: { class: 'asy-filter' },
    standalone: true
})
export class AsyFilterDirective<T> {
    dataSource = input.required<AsyTableDataSource<T>>();

    /** Collection of all registered filterables that this directive manages. */
    filterables = new Map<string, AsyFilterable>();

    filters = new Map<string, object>();

    /**
     * Register function to be used by the contained AsyFilterables. Adds the AsyFilterable to the
     * collection of AsyFilterables.
     */
    register(filterable: AsyFilterable): void {
        if (!filterable.id) {
            throw Error(`AsyFilterHeaderComponent must be provided with a unique id.`);
        }

        if (this.filterables.has(filterable.id)) {
            throw Error(`Cannot have two AsyFilterables with the same id (${filterable.id}).`);
        }

        this.filterables.set(filterable.id, filterable);
    }

    /**
     * Unregister function to be used by the contained AsyFilterables. Removes the AsyFilterable from the
     * collection of contained AsyFilterables.
     */
    deregister(filterable: AsyFilterable): void {
        this.filterables.delete(filterable.id);
    }

    filter(id: string, query: object): void {
        this.filters.set(id, query);
        this.dataSource().filter(this._buildFilter());
    }

    clearFilter(): void {
        this.filters.clear();
        this.filterables.forEach((f) => {
            f.clearFilter();
        });
    }

    _buildFilter() {
        const queries = [...this.filters.values()].filter((q) => !isEmpty(q));
        if (queries.length === 0) {
            return {};
        }
        return { $and: queries };
    }
}